Lithium ion batteries provide good electrochemical performance and high capacity and are used as energy storage devices for a variety of applications, such as solar energy, wind energy, hydroelectricity, and electric cars. The demand for higher capacity storage can be met by improving the rate capability and energy density of lithium ion batteries. For example, to enhance the electrochemical performance of lithium ion batteries having lithium iron phosphate cathodes, the cathodes can be coated with carbon, doped with metal, and/or formed of small particles.